Using PATCH for update / edit

[Antarian]

Description
In this line in code

admin/src/hydra/dataProvider.js

Line 340 in 5badc1f

method: 'PUT',

is forced PUT for update operation. s it posible to somehow detect if schema is using put or patch? JsonLD is displaying this information.

[alanpoulain]

React admin always sends all the data, this behavior would need to be changed beforehand for this feature to be useful.

[Antarian]

yes, but specific PATCH format (merge-patch+json) may send all the data. And I think I found something about this partial PATCH in React Admin issues. Will send link here in a moment.
Maybe some kind of manual config here would be useful, but that is sounding kind of like a hack. As ApiPlatform is creating new child entity when PUT is used and overriding same entity when PATCH is used. Which is my required and expected behaviour for EDIT.
So far I retreat to hack/decorate serializer/normalizer to alter this behaviour of PUT in ApiPlatform when id is sent. If I will be successful.

[Antarian]

Probably more relevant than anything below is this piece of code from React Admin repo:
https://github.com/marmelab/react-admin/blob/master/packages/ra-core/src/actions/dataActions/crudUpdate.ts
which is using "previousData".

marmelab/react-admin#256

and also this one, but not sure how much is it related:
josx/ra-data-feathers#20
with this PR
https://github.com/josx/ra-data-feathers/pull/49/files

But this may be more relevant:
marmelab/react-admin#338
with related PR
https://github.com/marmelab/react-admin/pull/351/files

I am hopefully not spamming this, will go through internal code and try to understand how this works.

[vaheeds]

I am using react-admin as the front-end. In my case, the backend API uses some sort of validation and does not allow _id to be modified. So it cannot accept PUT requests and throws an error when the _id field is presented in the PATCH request. So I have to use PATCH and I want to send modified fields only.
How can I overcome this issue?

[vaheeds]

I figured it out in a custom data provider:

  update: (resource, params) =>
    httpClient(`${apiUrl}/${resource}/${params.id}`, {
      method: 'PATCH',
      body: JSON.stringify(diff(params.data, params.previousData)),
    }).then(({ json }) => ({ data: json })),

where the diff function is:

const diff = (object, base) => {
  return transform(object, (result, value, key) => {
    if (!isEqual(value, base[key])) {
      result[key] =
        isObject(value) && isObject(base[key]) ? diff(value, base[key]) : value;
    }
  });
};

now, only the altered fielt sent in request body with a PATCH method.

[vincentchalamon]

Fixed by #589, available in v4.0.3